[Method and design of the Telephone Health Survey 2003].

Telephone surveys are increasingly being used in public health research, also in Germany. In 2003 the Robert Koch Institute completed the first nationwide telephone survey predominantly on conditions and prevalence of selected chronic diseases (GSTel03). Its findings are presented in this publication. The tasks of planning, implementation and realization of procedures used in telephone surveys differ in many aspects from other modes of data collection. This article deals with the most important methodological aspects that were implemented and used in the course of the GSTel03 to ensure a high level of data quality. These include sample design, questionnaire development and the process of data collection (including the recruitment and training of the staff). Finally steps of data preparation for analysis including weighting procedures are described and calculation of contact and cooperation rates are reported.